What other options do I have to get an ad placed onto the landing page?
What other options do I have to get an ad placed onto the landing page?
I'd use the space myself for building an e-mail list, Twitter following, Facebook following, or similar which could then be used to make money further down the line. I don't know much about your game mod/project but if everyone going through that page is an avid Steam user and gamer, if you could get 100k people following on Twitter, on an e-mail list, on Facebook, etc, that's a very valuable audience for many people.
TL;dr - Don't let third parties advertise on the page, use the space to build your own audience, then sell advertising/make money on the back end.
There are other ads providers out there that have very good fill rates, I would look at them.
I am still trying to balance how much we talk about other providers on our site vs general themes which are common for all platforms.
There is no formidable AdSense competitor or alternative.
[1] http://steamcommunity.com/sharedfiles/filedetails/?id=118824...